A surfactant except quaternary ammonium salt generally has only scarce or very weak bactericidal activity by itself In addition, it has not been known that addition of such surfactant to a different material having scarce or very weak bactericidal activity results in reinforcement of the bactericidal power.
Thus, the present invention aims at exploring an unknown use of a surfactant heretofore never considered a bactericidal agent, by adding the surfactant to a different material.